1. Field of the Invention
The invention concerns a receiver coil, in particular a local coil, to measure x-nuclei signals in magnetic resonance spectroscopy, of the type having at least one filter connected in a first signal path to filter out radio-frequency pulses radiated via a transmission coil during a measurement. The invention also concerns a magnetic resonance apparatus.
2. Description of the Prior Art
In the field of magnetic resonance spectroscopy it is also known to measure signals from non-proton nuclei, known as x-nuclei. Achieving a sufficient signal-to-noise ratio in view of the reduced sensitivity of many nuclei is thereby of central importance. It is known to use a decoupling technique to increase the signal-to-noise ratio and to simplify multiplet signals. However, the decoupling technique requires the radiation of radio-frequency pulses during the data acquisition (the measurement). In order for the radio-frequency pulses to not negatively influence the measurement, it is known to use at least one filter in the reception path and in the transmission path. However, these filters produce an attenuation of the signal which leads to a decrease of the signal-to-noise ratio in the signal path of the reception coil.
Reception coils with such filters plugged into the signal path are known, for example in 31P-1H heart-liver coils and the like. Such a reception coil can also include a separate filter box that is inserted into the reception path, but this leads to a more complicated and more expensive workflow and generates additional error sources.
The reduction of the signal-to-noise ratio that is described above by the attenuation of the signal due to the additional filters is disadvantageous when specific measurements do not require any additional radio-frequency pulses at all for decoupling.